[C:1]([C:3]1[CH:4]=[C:5]([O:13][CH3:14])[C:6]([C:9]([O:11]C)=[O:10])=[N:7][CH:8]=1)#[N:2].[OH-].[Na+].Cl>C1COCC1>[C:1]([C:3]1[CH:4]=[C:5]([O:13][CH3:14])[C:6]([C:9]([OH:11])=[O:10])=[N:7][CH:8]=1)#[N:2]In a 1-L flask, the methyl 5-cyano-3-methoxypicolinate (step 2, 4.51 g, 23.5 mmol) was taken up in THF (74 mL). The suspension was cooled to 0° C., and sodium hydroxide (1M, 24.64 mL, 24.64 mmol) was added. After 1 h, the reaction was concentrated under reduced pressure. The residue was taken up in 100 mL of water, and the aqueous phase was extracted with diethyl ether (50 mL), which was discarded. The aqueous phase was acidified with HCl (5M, 5.16 mL, 25.8 mmol). The aqueous phase was extracted with DCM (11×150 mL). The combined organic extracts were dried over MgSO4 and the filtrate was concentrated under reduced pressure to afford the title compound as a white solid. MS m/z=179 [M+H]+. Calculated for C8H6N2O3: 178. 1H NMR in CDCl3 δ: 8.48 (d, 1H, J=1.6), 7.71 (d, 1H, J=1.6), 4.08 (s, 3H).
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